EP0376809B1 - Method and device for deep-drawing sheet materials on an elsatic formation lower die - Google Patents

Method and device for deep-drawing sheet materials on an elsatic formation lower die Download PDF

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Publication number
EP0376809B1
EP0376809B1 EP89403590A EP89403590A EP0376809B1 EP 0376809 B1 EP0376809 B1 EP 0376809B1 EP 89403590 A EP89403590 A EP 89403590A EP 89403590 A EP89403590 A EP 89403590A EP 0376809 B1 EP0376809 B1 EP 0376809B1
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EP
European Patent Office
Prior art keywords
pressing device
piston
cushion
elastic cushion
interacting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP89403590A
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German (de)
French (fr)
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EP0376809A1 (en
Inventor
Gabriel De Smet
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Isoform SNC
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Isoform SNC
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Priority to AT89403590T priority Critical patent/ATE88383T1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/10—Stamping using yieldable or resilient pads
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49805—Shaping by direct application of fluent pressure

Definitions

  • the present invention relates to a device for stamping sheet materials on an elastic forming matrix.
  • FR-A-2 564 339 and FR-A-2 590 814 which represents the closest state of the art, have been proposed for a drawing process on an elastic cushion.
  • the sheet blank to be formed is placed on an elastic cushion, an external slider supporting a blank holder is applied to the peripheral part of the sheet blank so as to cause the mass of the elastic cushion to creep to deform the central part of the sheet blank by giving it at the end of the preforming step, a surface substantially equal to the surface of the finished part to be obtained, then a central slide acting by a punch is applied to the central part of the sheet blank to conform the part to its final form.
  • This process allows the drawing of a sheet material, in particular of a material with low elongation, which can in particular be a metal sheet, for example of steel, although this process is not limited to the drawing of metallic foil, but can be applied to plastic materials and any other composite material.
  • the cushion of elastic material is described as being able in particular to be a composite support consisting of a substantially parallelepipedic mass based on a silicone elastomer of low Shore hardness, which can be covered, on its upper face, and on all or part from its side faces of a relatively thin envelope made of a more resistant and harder material.
  • the blank holder applied to the peripheral part of the blank sheet metal causes the mass of the elastic cushion to creep in order to deform the central part of said blank while giving it, at the end of the preforming step, a surface substantially equal to the surface of the finished part to be obtained.
  • the descent of the punch for the final shaping of the sheet blank causes an increase in pressure in the cushion, and a difference in volume of said cushion between the preforming step and the shaping step, which it is necessary to compensate by decompression of the elastic cushion in order to avoid deformation of the stamped part by relaxation reaction of the elastic material making up the cushion.
  • the present invention relates to a device for stamping sheet materials formed by a sheet blank placed on a support forming a lower blank holder, said device comprising a cushion of elastic material housed in a retention tank, means for preforming the sheet blank consisting of an external slider carrying an upper blank holder and means for definitive shaping of said sheet blank consisting of a central slide acting on a punch and means for absorbing the excess volume of the elastic cushion, characterized in that the absorption means are movable during the final shaping of the part, said displacement being regulated by a regulating member as a function, on the one hand, of the pressure applied by the cushion in an elastic material during said step and, on the other hand, the volume determined by the surface of the finished part to be obtained.
  • the stamping device shown in Figures 1 to 3 comprises a tank 2, the central part of which constitutes a housing for a cushion 6 made of an elastic material.
  • a frame 2a with a closed contour which constitutes a lower peripheral blank holder and which substantially follows the contour of the internal housing of the container 2 so as to be able to penetrate into said housing when the room.
  • the stamping device comprises a body 1 carried by an external slide, not shown, and the lower part of which constitutes an upper peripheral blank holder 1a.
  • the upper peripheral blank holder 1a has external dimensions slightly smaller than the outline of the internal housing of the container 2 so as to cooperate with the frame 2a and to penetrate into said housing.
  • the body 1 has a central well inside which penetrates a punch 4, the underside of which constitutes an imprint corresponding to the profile. of the finished part to be obtained.
  • the device also comprises means 10 for absorbing the excess volume of the elastic cushion 6 generated by the application of the punch 4 relative to that determined by the surface of the finished part to be obtained.
  • These means 10 consist of a vertically movable piston 11 constituting the bottom 5 of the tank 2 which for this purpose has a central opening 5a.
  • the piston 11 has its upper face applied against the elastic cushion 6 and cooperates with a member for regulating the movement of said piston formed in this embodiment by a multi-blade brake 12.
  • This multi-blade brake 12 comprises, on the one hand, upper friction plates 12a directed downwards and integral with the piston 11 and, on the other hand, lower friction plates 12b directed upwards and fixed on a soleplate 13 arranged below the bottom 5 of the tank 2 and at a determined interval.
  • the upper and lower friction plates 12a and 12b are interposed with one another.
  • the assembly constituted by the piston 11 and the strongly plates 12a is recalled by a spring 14 bearing on the sole 13.
  • the multi-blade brake 12 is controlled on each side by a clamping mechanism 15 constituted by a control cylinder 16, the piston 17 of which actuates a rod 18 articulated on two levers 19 and 20 forming a toggle for clamping the friction plates 12a and 12b.
  • a clamping mechanism 15 constituted by a control cylinder 16
  • the free end of the lever 19 is supported on a lateral rim 13a provided on the sole 13 and the free end of the lever 20 is secured to a small piston 21 which acts on the friction plates 12a and 12b.
  • the device operates as follows.
  • the body 1 is lowered by means of the external slide, not shown, from the press, so that the upper blank holder 1a comes into contact with the sheet blank 3 whose peripheral zone is progressively clamped between the lower blank holder 2a and the upper blank holder 1a to avoid scalloping.
  • the upper blank holder 1a performs in localized areas a falling of the edge of the sheet blank and compresses by reaction the elastic cushion 6.
  • the latter under the effect of this peripheral compression action, acts by creep on the central area of the sheet blank and cause its deformation.
  • the swelling of the central part of the sheet blank is limited by the bottom of the punch 4 in order to avoid uncontrolled erratic deformations.
  • a suitable mechanism controls the jacks 16, in such a way that, under the effect of the pistons 17 of said jacks, the rods 18 act on the levers 19 and 20 of each mechanism 15 and cause the displacement towards each other of the small pistons 21 which thus clamp the friction plates 12a and 12b against each other.
  • the punch 4 descends to its low position and causes the final forming of the central part of the blank 3 preformed during the previous operation.
  • a suitable mechanism not shown, controlled for example by a pressure sensor placed in the elastic cushion 6, actuates the jacks 16 which act on the levers 19 and 20, so as to loosen more or less the friction plates 12a and 12b, which makes it possible to regulate the movement of the piston 11 and to absorb the excess volume of the elastic cushion 6 generated by the application of the punch 4 relative to that determined by the surface of the finished part to be obtained.
  • the jacks 16 completely loosen the friction plates 12a and 12b and as no more pressure exists in the elastic cushion 6, the return spring 14 , which no longer has to overcome than the weight of the movable piston 11, of the elastic cushion 6 and various frictions, causes the ascent of said movable piston.
  • the means 10 make it possible, during the final shaping operation of the part, to absorb the excess volume of the elastic cushion 6 by regulating the movement of the piston 11 by the multi-blade brake 12.
  • the means 10 for absorbing the excess volume of the elastic cushion 6 are constituted by a piston 31 in contact with said elastic cushion 6 and integral in rotation with a reversible screw 30 cooperating with a belt brake (33-36) which constitutes the member for regulating the movement of said piston.
  • the bottom 5 of the container containing the elastic cushion 6 is in contact with the sole 13 and provides therewith a central cavity 32 in which a cylindrical rotating nut 33 is disposed.
  • a friction stop 34 is interposed between the rotating nut 33 and the sole 13.
  • the rotating nut 33 comprises a central orifice 33a provided with an internal screw pitch cooperating with the screw 30.
  • a spring 35 is placed in the orifice 33a between the bottom of the screw 30 and the sole 13.
  • the rotating nut 33 has on its periphery a groove 33b in which a braking belt 36 is placed.
  • the braking belt 36 surrounds the rotating nut 33 and has one of its ends 35a immobilized and the other of its ends 36b secured by a hooking mechanism 37 with the end of a rod 38 of a jack 39 for controlling the tension of said braking belt.
  • the jack 39 When lowering the upper blank holder for preforming the sheet blank, the jack 39 exerts a tension on the braking belt 36, which has the effect of immobilizing the nut 33, the screw 30 and the piston 31 , thereby preventing the elastic cushion 6 from creeping down.
  • the jack 39 controlled by a suitable mechanism, not shown, more or less tightens the braking belt 36, which makes it possible to regulate the movement of the piston 31 and to absorb the excess volume of the elastic cushion 6 relative to that determined by the surface of the finished part to be obtained.
  • the return spring 35 causes the piston 31 to rise under the action of the screw 30.
  • the rotary nut 33 comprises on its periphery meshing means constituted by a toothed groove 33c cooperating with an endless screw 40 controlled, for example, by a stepping motor, not shown, or by any other suitable means .
  • the means 10 for absorbing the excess volume of the elastic cushion 6, at the time of the final shaping of the part are constituted by a hydraulic cylinder 50.
  • the bottom 5 of the tank is supported on the sole 13 and provides therewith a cylindrical cavity 51 in which is disposed a cylinder 52 forming an internal chamber 53 filled with a fluid.
  • the bottom 5 of the tank consists of a piston 54, the upper face of which is in contact with the elastic cushion 6 and which comprises at its lower part a cylindrical base 55 sliding inside the cylinder 32.
  • the cylindrical base 55 comprises at its periphery of the sealing members 55a.
  • the hydraulic control circuit of the jack 50 comprises a pipe 56, one end of which opens into the internal chamber 53 below the base. 55 and the other end of which is connected to a fluid reservoir 57.
  • a pressure reducer 58 with proportional control programmed electrically or mechanically or pneumatically as a function of the desired pressure in the elastic cushion 6 and, on the other hand, a non-return valve 59 authorizing the passage of the fluid from the chamber 53 to the reservoir 57.
  • Line 56 also includes, upstream of the pressure reducer 58, a bypass constituted by a line 60 comprising a non-return valve 61 allowing the passage of the fluid from the reservoir 57 to the chamber 53 and a pump 62 withdrawing the fluid from the reservoir 57 .
  • the hydraulic circuit for controlling the jack 50 comprises a pipe 65, one end of which opens into the internal chamber 53 below the base 55 of the piston 54 and the other end of which is connected to the reservoir 57. On this pipe is mounted only pressure reducer 58.
  • the hydraulic circuit also includes another pipe 66, one end of which opens into the internal chamber 53 above the base 55 and the other end of which is connected to the reservoir 57.
  • a return spring 67 is placed in the internal chamber 53 between the base 55 and the sole 13 to return the piston 54 to its initial position after the final shaping step.
  • the hydraulic circuit makes it possible, via the piston 54, to absorb the excess volume of the elastic cushion during the shaping step final of the part, by regulating the displacements of the piston 54 relative to the finished part to be obtained.
  • the means 10 for absorbing the excess volume of the elastic cushion 6, at the time of the final shaping of the part are constituted by a hydraulic valve regulated by a pneumatic valve.
  • the bottom 5 of the tank is supported on the sole 13 and provides therewith a cylindrical cavity 70 in which is disposed a cylinder 71 forming an internal chamber 72.
  • the cylinder 71 has a diameter smaller than the diameter internal of the retention tank and rests on a support plate 73 placed on the base 13.
  • the bottom 5 of the tank consists of a piston 74, the upper face of which is in contact with the elastic cushion 6 and which comprises at its lower part a cylindrical extension 75 sliding inside the cylinder 71.
  • the piston 74 is recalled by springs 92 arranged between the bottom of the cylindrical extension 75 and the plate 73.
  • a bowl 77 which comprises a lower skirt 76a bearing on the plate 73 and the upper wall 76b of which is pierced with a central orifice 77.
  • the bowl 76 cleans with the piston 74 an upper chamber 78 and has an internal chamber 79 in which slides a small piston 80 which has on its upper face a valve 81 cooperating with the lower part of the orifice 77 forming a valve seat.
  • the bowl 76 has an outside diameter slightly smaller than the diameter inside of the cylindrical extension 75 of the piston 74 so as to provide an annular space 82 bringing the upper chamber 78 into communication with the chamber 72.
  • the small piston 80 is returned upwards by springs 83 bearing on the sole 13 and its downward travel is limited by a stop 84.
  • the skirt 76a of the bowl 76 and the support plate 73 are pierced with small channels 85 and 86 respectively putting the upper chamber 78 into communication with the cavity 70.
  • the support plate 73 is pierced with small orifices 87 fitted with non-return valves which put the chamber 72 in communication with the small channels 86.
  • the cavity 70 forms a fluid reservoir which fills the chambers 72, 78 and 79 as well as the small channels 85 and 86.
  • valve 90 When lowering the upper blank holder for preforming the part, the valve 90 is open and the compressed air acts on the small piston 80 so as to apply the valve 81 to its seat.
  • the orifice 77 is closed, which prevents the fluid from flowing from the chamber 78 towards the chamber 79 and consequently the elastic cushion 6 from flowing downwards.
  • the small valves arranged in the orifices 87 open and the fluid flows from the cavity 70 towards the chamber 72 via the channels 86 and the orifices 87, then from the chamber 72 to the chamber 78 passing through the annular space 82.
  • the body 1 consists of an upper part 100a secured to the external slide, not shown, of the press, and of a separate lower part 100b, the lower face of which constitutes the clamp. upper peripheral blank.
  • This member 101 can be constituted for example by a spring or by a jack or by any other another suitable system limiting the penetration height of the upper blank holder in the cushion when the pressure in said cushion becomes greater than a determined value.
  • the means for absorbing the excess volume of the elastic cushion 6 can also be formed by at least one side wall of the tank 2 cooperating with a member constituted, for example by at least one spring or a jack, making it possible to regulate the movement of said wall lateral as a function of the pressure exerted in the elastic cushion.
  • the device according to the present invention is applicable not only in the case where the sheet metal blank rests on a lower blank holder formed by a frame, but also in the case where the sheet blank rests directly on the elastic cushion , according to FR-A-2,564,339, and in the case where the sheet blank is in abutment on the upper part of the retention tank of the elastic cushion, according to FR-A-2,590,814.

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  • Mechanical Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
  • Press Drives And Press Lines (AREA)
  • Presses And Accessory Devices Thereof (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Soil Working Implements (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Auxiliary Devices For And Details Of Packaging Control (AREA)
  • Manipulator (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
  • Braking Arrangements (AREA)

Abstract

Method for deep-drawing sheet materials, of the type comprising a pad (6) made of an elastic material, according to which a sheet metal blank (3) to be formed is disposed on a holder forming a lower peripheral pressure plate (2a), an upper pressure plate (1a) is applied onto the peripheral portion of the sheet metal blank (3) for the preforming of the said blank and then a punch (4) is applied onto the central portion of the sheet metal blank (3) for the final forming, characterised in that, during the final forming, the excess volume of the elastic pad (6), generated by the application of the punch (4), in relation to that determined by the surface of the finished part to be obtained, is absorbed. <IMAGE>

Description

La présente invention a pour objet un dispositif d'emboutissage de matériaux en feuille sur une matrice de formage élastique.The present invention relates to a device for stamping sheet materials on an elastic forming matrix.

On a proposé, dans les FR-A-2 564 339 et FR-A-2 590 814 qui représente l'état de la technique le plus proche, un procédé d'emboutissage sur coussin élastique. Selon ce procédé, on dispose le flan de tôle à former sur un coussin élastique, on applique un coulisseau extérieur supportant un serre-flan sur la partie périphérique du flan de tôle de façon à provoquer le fluage de la masse du coussin élastique pour déformer la partie centrale du flan de tôle en lui conférant en fin d'étape de préformage, une surface sensiblement égale à la surface de la pièce finie à obtenir, puis on applique un coulisseau central agissant par un poinçon sur la partie centrale du flan de tôle pour conformer la pièce à sa forme définitive.FR-A-2 564 339 and FR-A-2 590 814, which represents the closest state of the art, have been proposed for a drawing process on an elastic cushion. According to this method, the sheet blank to be formed is placed on an elastic cushion, an external slider supporting a blank holder is applied to the peripheral part of the sheet blank so as to cause the mass of the elastic cushion to creep to deform the central part of the sheet blank by giving it at the end of the preforming step, a surface substantially equal to the surface of the finished part to be obtained, then a central slide acting by a punch is applied to the central part of the sheet blank to conform the part to its final form.

Ce procédé permet l'emboutissage d'un matériau en feuille, en particulier d'un matériau à faible allongement, qui peut être notamment une tôle métallique, par exemple d'acier, bien que ce procédé ne soit pas limité à l'emboutissage de feuille métallique, mais puisse s'appliquer à des matériaux plastiques et à tout autre matériau composite.This process allows the drawing of a sheet material, in particular of a material with low elongation, which can in particular be a metal sheet, for example of steel, although this process is not limited to the drawing of metallic foil, but can be applied to plastic materials and any other composite material.

Le coussin en matériau élastique est décrit comme pouvant notamment être un support composite constitué d'une masse sensiblement parallèlépipèdique à base d'un élastomère de silicone de faible dureté Shore, pouvant être recouvert, sur sa face supérieure, et sur la totalité ou une partie de ses faces latérales d'une enveloppe relativement mince en un matériau plus résistant et plus dur.The cushion of elastic material is described as being able in particular to be a composite support consisting of a substantially parallelepipedic mass based on a silicone elastomer of low Shore hardness, which can be covered, on its upper face, and on all or part from its side faces of a relatively thin envelope made of a more resistant and harder material.

Au cours de l'étape de préformage, le serre-flan appliqué sur la partie périphérique du flan de tôle provoque le fluage de la masse du coussin élastique pour déformer la partie centrale dudit flan tout en lui conférant, en fin d'étape de préformage, une surface sensiblement égale à la surface de la pièce finie à obtenir.During the preforming step, the blank holder applied to the peripheral part of the blank sheet metal causes the mass of the elastic cushion to creep in order to deform the central part of said blank while giving it, at the end of the preforming step, a surface substantially equal to the surface of the finished part to be obtained.

Mais, la descente du poinçon pour la conformation finale du flan de tôle entraîne une élévation de pression dans le coussin, et une différence de volume dudit coussin entre l'étape de préformage et l'étape de conformation, qu'il est nécessaire de compenser par une décompression du coussin élastique afin d'éviter la déformation de la pièce emboutie par réaction de détente du matériau élastique composant le coussin.However, the descent of the punch for the final shaping of the sheet blank causes an increase in pressure in the cushion, and a difference in volume of said cushion between the preforming step and the shaping step, which it is necessary to compensate by decompression of the elastic cushion in order to avoid deformation of the stamped part by relaxation reaction of the elastic material making up the cushion.

La présente invention a pour objet un dispositif d'emboutissage de matériaux en feuille formés par un flan de tôle placé sur un support formant un serre-flan inférieur, ledit dispositif comprenant un coussin en un matériau élastique logé dans un bac de rétention, des moyens de préformage du flan de tôle constitués par un coulisseau extérieur portant un serre-flan supérieur et des moyens de formage définitif dudit flan de tôle constitués par un coulisseau central agissant sur un poinçon et des moyens d'absorption du volume excédentaire du coussin élastique, caractérisé en ce que les moyens d'absorption sont déplaçables au cours du formage définitif de la pièce, ledit déplacement étant réglé par un organe de régulation en fonction, d'une part, de la pression appliquée par le coussin en un matériau élastique au cours de ladite étape et, d'autre part, du volume déterminé par la surface de la pièce finie à obtenir.The present invention relates to a device for stamping sheet materials formed by a sheet blank placed on a support forming a lower blank holder, said device comprising a cushion of elastic material housed in a retention tank, means for preforming the sheet blank consisting of an external slider carrying an upper blank holder and means for definitive shaping of said sheet blank consisting of a central slide acting on a punch and means for absorbing the excess volume of the elastic cushion, characterized in that the absorption means are movable during the final shaping of the part, said displacement being regulated by a regulating member as a function, on the one hand, of the pressure applied by the cushion in an elastic material during said step and, on the other hand, the volume determined by the surface of the finished part to be obtained.

Selon d'autres caractéristiques de l'invention, les moyens d'absorption du volume excédentaire du coussin élastique sont constitués par :

  • le fond du bac de rétention du coussin,
  • au moins une paroi latérale du bac de rétention du coussin,
  • le serre-flan supérieur.
According to other characteristics of the invention, the means for absorbing the excess volume of the elastic cushion consist of:
  • the bottom of the cushion retention tank,
  • at least one side wall of the cushion retention tank,
  • the upper hold-down.

L'invention sera mieux comprise à l'aide de la description qui va suivre, donnée uniquement à titre d'exemple et faite en référence aux dessins annexés, sur lesquels :

  • les Figs. 1 à 3 s ont des vues schématiques en coupe du dispositif d'emboutissage selon l'invention, au cours des étapes successives de formage d'une pièce,
  • la Fig. 4 est une vue schématique en coupe d'une première variante du dispositif d'emboutissage selon l'invention,
  • la Fig. 5 est une vue à plus grande échelle en coupe selon la ligne 5-5 de la Fig. 4,
  • la Fig. 6 est une vue schématique en coupe d'une seconde variante du dispositif d'emboutissage selon l'invention,
  • la Fig. 7 est une vue schématique en coupe d'une troisième variante du dispositif d'emboutissage selon l'invention,
  • la Fig. 8 est une vue schématique en coupe d'une quatrième variante du dispositif d'emboutissage selon l'invention,
  • les Figs. 9, 10 et 11 sont des vues schématiques en coupe d'une cinquième variante du dispositif d'emboutissage, selon l'invention, au cours des étapes successives de formage d'une pièce, et
  • la Fig. 12 est une vue schématique en coupe d'une sixième variante du dispositif d'emboutissage selon l'invention.
The invention will be better understood with the aid of the description which follows, given solely by way of example and made with reference to the appended drawings, in which:
  • Figs. 1 to 3 s have schematic sectional views of the stamping device according to the invention, during the successive stages of forming a part,
  • Fig. 4 is a schematic sectional view of a first variant of the stamping device according to the invention,
  • Fig. 5 is an enlarged sectional view along line 5-5 of FIG. 4,
  • Fig. 6 is a schematic sectional view of a second variant of the drawing device according to the invention,
  • Fig. 7 is a schematic sectional view of a third variant of the drawing device according to the invention,
  • Fig. 8 is a schematic sectional view of a fourth variant of the drawing device according to the invention,
  • Figs. 9, 10 and 11 are schematic sectional views of a fifth variant of the stamping device according to the invention, during the successive stages of forming a part, and
  • Fig. 12 is a schematic sectional view of a sixth variant of the drawing device according to the invention.

Le dispositif d'emboutissage représenté aux figures 1 à 3 comprend un bac 2 dont la partie centrale constitue un logement pour un coussin 6 en un matériau élastique.The stamping device shown in Figures 1 to 3 comprises a tank 2, the central part of which constitutes a housing for a cushion 6 made of an elastic material.

Sur la face supérieure du coussin élastique 6 est disposée un cadre 2a à contour fermé qui constitue un serre-flan périphérique inférieur et qui épouse sensiblement le contour du logement interne du bac 2 de façon à pouvoir pénétrer dans ledit logement au moment du formage de la pièce.On the upper face of the elastic cushion 6 is disposed a frame 2a with a closed contour which constitutes a lower peripheral blank holder and which substantially follows the contour of the internal housing of the container 2 so as to be able to penetrate into said housing when the room.

Au-dessus du bac 2, le dispositif d'emboutissage comporte un corps 1 porté par un coulisseau extérieur, non représenté, et dont la partie inférieure constitue un serre-flan périphérique supérieur 1a.Above tank 2, the stamping device comprises a body 1 carried by an external slide, not shown, and the lower part of which constitutes an upper peripheral blank holder 1a.

Le serre-flan périphérique supérieur 1a a des dimensions extérieures légèrement inférieures au contour du logement interne du bac 2 de façon à coopérer avec le cadre 2a et à pénétrer dans ledit logement.The upper peripheral blank holder 1a has external dimensions slightly smaller than the outline of the internal housing of the container 2 so as to cooperate with the frame 2a and to penetrate into said housing.

Le corps 1 comporte un puits central à l'intérieur duquel pénètre un poinçon 4 dont la face inférieure constitue une empreinte correspondant au profil de la pièce finie à obtenir.The body 1 has a central well inside which penetrates a punch 4, the underside of which constitutes an imprint corresponding to the profile. of the finished part to be obtained.

Le dispositif comporte également des moyens 10 d'absorption du volume excédentaire du coussin élastique 6 engendré par l'application du poinçon 4 par rapport à celui déterminé par la surface de pièce finie à obtenir.The device also comprises means 10 for absorbing the excess volume of the elastic cushion 6 generated by the application of the punch 4 relative to that determined by the surface of the finished part to be obtained.

Ces moyens 10 sont constitués par un piston 11 mobile verticalement constituant le fond 5 du bac 2 qui comporte à cet effet une ouverture centrale 5a. Le piston 11 a sa face supérieure appliquée contre le coussin élastique 6 et coopère avec un organe de régulation du déplacement dudit piston formé dans cet exemple de réalisation par un frein multi-lames 12.These means 10 consist of a vertically movable piston 11 constituting the bottom 5 of the tank 2 which for this purpose has a central opening 5a. The piston 11 has its upper face applied against the elastic cushion 6 and cooperates with a member for regulating the movement of said piston formed in this embodiment by a multi-blade brake 12.

Ce frein multi-lames 12 comporte, d'une part, des plaques de frottement supérieures 12a dirigées vers le bas et solidaires du piston 11 et, d'autre part, des plaques de frottement inférieures 12b dirigées vers le haut et fixées sur une semelle 13 disposée au-dessous du fond 5 du bac 2 et à un intervalle déterminé. Les plaques de frottement supérieures et inférieures 12a et 12b sont intercalées les unes entre les autres.This multi-blade brake 12 comprises, on the one hand, upper friction plates 12a directed downwards and integral with the piston 11 and, on the other hand, lower friction plates 12b directed upwards and fixed on a soleplate 13 arranged below the bottom 5 of the tank 2 and at a determined interval. The upper and lower friction plates 12a and 12b are interposed with one another.

L'ensemble constitué par le piston 11 et les plaques de forttement 12a est rappelé par un ressort 14 prenant appui sur la semelle 13.The assembly constituted by the piston 11 and the strongly plates 12a is recalled by a spring 14 bearing on the sole 13.

Le frein multi-lames 12 est commandé de chaque côté par un mécanisme de serrage 15 constitué par un vérin de commande 16 dont le piston 17 actionne une tige 18 articulée sur deux leviers 19 et 20 formant une genouillère de serrage des plaques de frottement 12a et 12b. A cet effet, l'extrémité libre du levier 19 prend appui sur un rebord latéral 13a prévu sur la semelle 13 et l'extrémité libre du levier 20 est solidaire d'un petit piston 21 qui agit sur les plaques de frottement 12a et 12b.The multi-blade brake 12 is controlled on each side by a clamping mechanism 15 constituted by a control cylinder 16, the piston 17 of which actuates a rod 18 articulated on two levers 19 and 20 forming a toggle for clamping the friction plates 12a and 12b. To this end, the free end of the lever 19 is supported on a lateral rim 13a provided on the sole 13 and the free end of the lever 20 is secured to a small piston 21 which acts on the friction plates 12a and 12b.

Le dispositif fonctionne de la manière suivante.The device operates as follows.

Dans l'étape de préformage illustrée à la Fig. 2, on fait descendre par l'intermédiaire du coulisseau extérieur, non représenté, de la presse, le corps 1 de telle manière que le serre-flan supérieur 1a entre en contact avec le flan de tôle 3 dont la zone périphérique est progressivement serrée entre le serre-flan inférieur 2a et le serre-flan supérieur 1a pour éviter son festonnage. Au cours de sa descente, le serre-flan supérieur 1a réalise dans des zones localisées un tombage du bord du flan de tôle et comprime par réaction le coussin élastique 6. Ce dernier, sous l'effet de cette action de compression périphérique, agit par fluage sur la zone centrale du flan de tôle et provoque sa déformation.In the preforming step illustrated in FIG. 2, the body 1 is lowered by means of the external slide, not shown, from the press, so that the upper blank holder 1a comes into contact with the sheet blank 3 whose peripheral zone is progressively clamped between the lower blank holder 2a and the upper blank holder 1a to avoid scalloping. During its descent, the upper blank holder 1a performs in localized areas a falling of the edge of the sheet blank and compresses by reaction the elastic cushion 6. The latter, under the effect of this peripheral compression action, acts by creep on the central area of the sheet blank and cause its deformation.

Le gonflement de la partie centrale du flan de tôle est limité par le fond du poinçon 4 afin d'éviter les déformations erratiques incontrôlées.The swelling of the central part of the sheet blank is limited by the bottom of the punch 4 in order to avoid uncontrolled erratic deformations.

Dès le début de la descente du serre-flan supérieur 1 , un mécanisme approprié, non représenté, commande les vérins 16, de telle manière que, sous l'effet des pistons 17 desdits vérins, les tiges 18 agissent sur les leviers 19 et 20 de chaque mécanisme 15 et provoquent le déplacement l'un vers l'autre des petits pistons 21 qui serrent ainsi les plaques de frottement 12a et 12b les unes contre les autres.From the start of the descent of the upper blank holder 1, a suitable mechanism, not shown, controls the jacks 16, in such a way that, under the effect of the pistons 17 of said jacks, the rods 18 act on the levers 19 and 20 of each mechanism 15 and cause the displacement towards each other of the small pistons 21 which thus clamp the friction plates 12a and 12b against each other.

De cette façon, durant cette opération de préformage, les plaques de frottement 12a et 12b sont appliquées les unes sur les autres et empêchent le piston mobile 11 de descendre sous l'effet de la pression exercée dans le coussin élastique 6 et, par conséquent, audit coussin élastique de fluer vers le bas.In this way, during this preforming operation, the friction plates 12a and 12b are applied one on the other and prevent the movable piston 11 from going down under the effect of the pressure exerted in the elastic cushion 6 and, consequently, said elastic cushion to flow towards the low.

Pendant l'étape de conformation finale du flan de tôle 3 représentée à la Fig. 3, le poinçon 4 descend à sa position basse et provoque le formage final de la partie centrale du flan 3 préformée au cours de l'opération précédente.During the final shaping step of the sheet blank 3 shown in FIG. 3, the punch 4 descends to its low position and causes the final forming of the central part of the blank 3 preformed during the previous operation.

Les contraintes dues à l'appui du poinçon 4 sur le sommet du flan de tôle 3 provoquent le déplacement de ce flan dans tout le volume disponible et permettent ainsi la réalisation finale de la pièce avec un minimum de variations d'épaisseur.The stresses due to the support of the punch 4 on the top of the sheet blank 3 cause the displacement of this blank in the entire available volume and thus allow the final production of the part with a minimum of thickness variations.

Un mécanisme approprié, non représenté, commandé par exemple par un capteur de pression disposé dans le coussin élastique 6, actionne les vérins 16 qui agissent sur les leviers 19 et 20, de façon à desserrer plus ou moins les plaques de frottement 12a et 12b, ce qui permet de réguler le déplacement du piston 11 et d'absorber le volume excédentaire du coussin élastique 6 engendré par l'application du poinçon 4 par rapport à celui déterminé par la surface de la pièce finie à obtenir.A suitable mechanism, not shown, controlled for example by a pressure sensor placed in the elastic cushion 6, actuates the jacks 16 which act on the levers 19 and 20, so as to loosen more or less the friction plates 12a and 12b, which makes it possible to regulate the movement of the piston 11 and to absorb the excess volume of the elastic cushion 6 generated by the application of the punch 4 relative to that determined by the surface of the finished part to be obtained.

En fin de cycle, après la remontée du poinçon 4 et du serre-flan supérieur 1a, les vérins 16 desserrent complètement les plaques de frottement 12a et 12b et comme plus aucune pression n'existe dans le coussin élastique 6, le ressort de rappel 14, qui n'a plus à vaincre que le poids du piston mobile 11, du coussin élastique 6 et divers frottements, provoque la remontée dudit piston mobile.At the end of the cycle, after the ascent of the punch 4 and of the upper blank holder 1a, the jacks 16 completely loosen the friction plates 12a and 12b and as no more pressure exists in the elastic cushion 6, the return spring 14 , which no longer has to overcome than the weight of the movable piston 11, of the elastic cushion 6 and various frictions, causes the ascent of said movable piston.

Par conséquent, les moyens 10 permettent, au cours de l'opération de conformation finale de la pièce, d'absorber le volume excédentaire du coussin élastique 6 en régulant le déplacement du piston 11 par le frein multi-lames 12.Consequently, the means 10 make it possible, during the final shaping operation of the part, to absorb the excess volume of the elastic cushion 6 by regulating the movement of the piston 11 by the multi-blade brake 12.

Selon une autre variante illustrée à la Fig. 4, les moyens 10 d'absorption du volume excédentaire du coussin élastique 6 sont constitués par un piston 31 en contact avec ledit coussin élastique 6 et solidaire en rotation avec une vis réversible 30 coopérant avec un frein à courroie (33-36) qui constitue l'organe de régulation du déplacement dudit piston.According to another variant illustrated in FIG. 4, the means 10 for absorbing the excess volume of the elastic cushion 6 are constituted by a piston 31 in contact with said elastic cushion 6 and integral in rotation with a reversible screw 30 cooperating with a belt brake (33-36) which constitutes the member for regulating the movement of said piston.

Le fond 5 du bac contenant le coussin élastique 6 est en appui sur la semelle 13 et ménage avec celle-ci une cavité centrale 32 dans laquelle est disposé un écrou tournant cylindrique 33. Une butée de frottement 34 est interposée entre l'écrou tournant 33 et la semelle 13.The bottom 5 of the container containing the elastic cushion 6 is in contact with the sole 13 and provides therewith a central cavity 32 in which a cylindrical rotating nut 33 is disposed. A friction stop 34 is interposed between the rotating nut 33 and the sole 13.

L'écrou tournant 33 comporte un orifice central 33a muni d'un pas de vis interne coopérant avec la vis 30. Un ressort 35 est placé dans l'orifice 33a entre le fond de la vis 30 et la semelle 13.The rotating nut 33 comprises a central orifice 33a provided with an internal screw pitch cooperating with the screw 30. A spring 35 is placed in the orifice 33a between the bottom of the screw 30 and the sole 13.

D'autre part, l'écrou tournant 33 comporte sur sa périphérie une gorge 33b dans laquelle est placée une courroie de freinage 36.On the other hand, the rotating nut 33 has on its periphery a groove 33b in which a braking belt 36 is placed.

Comme on le voit sur la Fig. 5, la courroie de freinage 36 entoure l'écrou tournant 33 et a une de ses extrémités 35a immobilisée et l'autre de ses extrémités 36b solidaire par un mécanisme d'accrochage 37 avec l'extrémité d'une tige 38 d'un vérin 39 de commande de la tension de ladite courroie de freinage.As seen in Fig. 5, the braking belt 36 surrounds the rotating nut 33 and has one of its ends 35a immobilized and the other of its ends 36b secured by a hooking mechanism 37 with the end of a rod 38 of a jack 39 for controlling the tension of said braking belt.

Lors de la descente du serre-flan supérieur pour le préformage du flan de tôle, le vérin 39 exerce une tension sur la courroie de freinage 36, ce qui a pour effet d'immobiliser l'écrou 33, la vis 30 et le piston 31, empêchant ainsi le coussin élastique 6 de fluer vers le bas.When lowering the upper blank holder for preforming the sheet blank, the jack 39 exerts a tension on the braking belt 36, which has the effect of immobilizing the nut 33, the screw 30 and the piston 31 , thereby preventing the elastic cushion 6 from creeping down.

Pendant l'opération de formage final par le poinçon, le vérin 39 commandé par un mécanisme approprié, non représenté, tend plus ou moins la courroie de freinage 36, ce qui permet de réguler le déplacement du piston 31 et d'absorber le volume excédentaire du coussin élastique 6 par rapport à celui déterminé par la surface de la pièce finie à obtenir.During the final forming operation by the punch, the jack 39 controlled by a suitable mechanism, not shown, more or less tightens the braking belt 36, which makes it possible to regulate the movement of the piston 31 and to absorb the excess volume of the elastic cushion 6 relative to that determined by the surface of the finished part to be obtained.

En fin de cycle, après la remontée du poinçon et du serre-flan supérieur, le ressort de rappel 35 provoque la remontée du piston 31 sous l'action de la vis 30.At the end of the cycle, after raising the punch and the upper blank holder, the return spring 35 causes the piston 31 to rise under the action of the screw 30.

Dans la variante représentée à la Fig. 6. l'écrou tournant 33 comporte sur sa périphérie des moyens d'engrènement constitués par une gorge dentée 33c coopérant avec une vis sans fin 40 commandée, par exemple, par un moteur pas à pas, non représenté, ou par tout autre moyen approprié.In the variant shown in FIG. 6. the rotary nut 33 comprises on its periphery meshing means constituted by a toothed groove 33c cooperating with an endless screw 40 controlled, for example, by a stepping motor, not shown, or by any other suitable means .

Selon deux autres variantes représentées aux Figs. 7 et 8, les moyens 10 d'absorption du volume excédentaire du coussin élastique 6, au moment de la conformation finale de la pièce, sont constitués par un vérin hydraulique 50.According to two other variants shown in Figs. 7 and 8, the means 10 for absorbing the excess volume of the elastic cushion 6, at the time of the final shaping of the part, are constituted by a hydraulic cylinder 50.

A cet effet, le fond 5 du bac est en appui sur la semelle 13 et ménage avec celle-ci une cavité cylindrique 51 dans laquelle est disposé un cylindre 52 formant une chambre interne 53 remplie d'un fluide.To this end, the bottom 5 of the tank is supported on the sole 13 and provides therewith a cylindrical cavity 51 in which is disposed a cylinder 52 forming an internal chamber 53 filled with a fluid.

Le fond 5 du bac est constitué par un piston 54 dont la face supérieure est en contact avec le coussin élastique 6 et qui comporte à sa partie inférieure une embase cylindrique 55 coulissant à l'intérieur du cylindre 32. L'embase cylindrique 55 comporte à sa périphérie des organes d'étanchéité 55a.The bottom 5 of the tank consists of a piston 54, the upper face of which is in contact with the elastic cushion 6 and which comprises at its lower part a cylindrical base 55 sliding inside the cylinder 32. The cylindrical base 55 comprises at its periphery of the sealing members 55a.

Le circuit hydraulique de commande du vérin 50 comporte une conduite 56 dont l'une extrémité débouche dans la chambre interne 53 au-dessous de l'embase 55 et dont l'autre extrémité est reliée à un réservoir de fluide 57. Sur cette conduite 56 sont montés, d'une part, un réducteur de pression 58 à commande proportionnelle programmé électriquement ou mécaniquement ou pneumatiquement en fonction de la pression désirée dans le coussin élastique 6 et, d'autre part, un clapet anti-retour 59 autorisant le passage du fluide de la chambre 53 vers le réservoir 57.The hydraulic control circuit of the jack 50 comprises a pipe 56, one end of which opens into the internal chamber 53 below the base. 55 and the other end of which is connected to a fluid reservoir 57. On this pipe 56 are mounted, on the one hand, a pressure reducer 58 with proportional control programmed electrically or mechanically or pneumatically as a function of the desired pressure in the elastic cushion 6 and, on the other hand, a non-return valve 59 authorizing the passage of the fluid from the chamber 53 to the reservoir 57.

La conduite 56 comporte également, en amont du réducteur de pression 58, une dérivation constituée par une conduite 60 comportant un clapet anti-retour 61 permettant le passage du fluide du réservoir 57 vers la chambre 53 et une pompe 62 prélevant le fluide du réservoir 57.Line 56 also includes, upstream of the pressure reducer 58, a bypass constituted by a line 60 comprising a non-return valve 61 allowing the passage of the fluid from the reservoir 57 to the chamber 53 and a pump 62 withdrawing the fluid from the reservoir 57 .

Dans la variante représentée à la Fig. 8, le circuit hydraulique de commande du vérin 50 comporte une conduite 65 dont une extrémité débouche dans la chambre interne 53 au-dessous de l'embase 55 du piston 54 et dont l'autre extrémité est raccordée au réservoir 57. Sur cette conduite est monté uniquement le réducteur de pression 58.In the variant shown in FIG. 8, the hydraulic circuit for controlling the jack 50 comprises a pipe 65, one end of which opens into the internal chamber 53 below the base 55 of the piston 54 and the other end of which is connected to the reservoir 57. On this pipe is mounted only pressure reducer 58.

Par ailleurs, le circuit hydraulique comporte également une autre conduite 66 dont une extrémité débouche dans la chambre interne 53 au-dessus de l'embase 55 et dont l'autre extrémité est raccordée au réservoir 57. Dans ce cas, un ressort de rappel 67 est placé dans la chambre interne 53 entre l'embase 55 et la semelle 13 pour ramener le piston 54 dans sa position initiale après l'étape de conformation finale.Furthermore, the hydraulic circuit also includes another pipe 66, one end of which opens into the internal chamber 53 above the base 55 and the other end of which is connected to the reservoir 57. In this case, a return spring 67 is placed in the internal chamber 53 between the base 55 and the sole 13 to return the piston 54 to its initial position after the final shaping step.

Dans ces deux exemples de réalisation, le circuit hydraulique permet, par l'intermédiaire du piston 54, d'absorber le volume excédentaire du coussin élastique au cours de l'étape de conformation finale de la pièce, en régulant les déplacements du piston 54 par rapport à la pièce finie à obtenir.In these two exemplary embodiments, the hydraulic circuit makes it possible, via the piston 54, to absorb the excess volume of the elastic cushion during the shaping step final of the part, by regulating the displacements of the piston 54 relative to the finished part to be obtained.

Selon une autre variante représentée aux Figs. 9 à 11, les moyens 10 d'absorption du volume excédentaire du coussin élastique 6, au moment de la conformation finale de la pièce, sont constitués par un clapet hydraulique régulé par une vanne pneumatique.According to another variant shown in Figs. 9 to 11, the means 10 for absorbing the excess volume of the elastic cushion 6, at the time of the final shaping of the part, are constituted by a hydraulic valve regulated by a pneumatic valve.

A cet effet, le fond 5 du bac est en appui sur la semelle 13 et ménage avec celle-ci une cavité cylindrique 70 dans laquelle est disposé un cylindre 71 formant une chambre interne 72. Le cylindre 71 a un diamètre plus petit que le diamètre interne du bac de rétention et repose sur une plaque d'appui 73 placée sur l'embase 13.For this purpose, the bottom 5 of the tank is supported on the sole 13 and provides therewith a cylindrical cavity 70 in which is disposed a cylinder 71 forming an internal chamber 72. The cylinder 71 has a diameter smaller than the diameter internal of the retention tank and rests on a support plate 73 placed on the base 13.

Le fond 5 du bac est constitué par un piston 74 dont la face supérieure est en contact avec le coussin élastique 6 et qui comporte à sa partie inférieure un prolongement cylindrique 75 coulissant à l'intérieur du cylindre 71. Le piston 74 est rappelé par des ressorts 92 disposés entre le fond du prolongement cylindrique 75 et la plaque 73.The bottom 5 of the tank consists of a piston 74, the upper face of which is in contact with the elastic cushion 6 and which comprises at its lower part a cylindrical extension 75 sliding inside the cylinder 71. The piston 74 is recalled by springs 92 arranged between the bottom of the cylindrical extension 75 and the plate 73.

A l'intérieur du prolongement cylindrique 75 du piston 74 est disposée une cuvette 77 qui comporte une jupe inférieure 76a en appui sur la plaque 73 et dont la paroi supérieure 76b est percée d'un orifice central 77. La cuvette 76 ménage avec le piston 74 une chambre supérieure 78 et comporte une chambre interne 79 dans laquelle coulisse un petit piston 80 qui comporte sur sa face supérieure un clapet 81 coopérant avec la partie inférieure de l'orifice 77 formant un siège de clapet.Inside the cylindrical extension 75 of the piston 74 is disposed a bowl 77 which comprises a lower skirt 76a bearing on the plate 73 and the upper wall 76b of which is pierced with a central orifice 77. The bowl 76 cleans with the piston 74 an upper chamber 78 and has an internal chamber 79 in which slides a small piston 80 which has on its upper face a valve 81 cooperating with the lower part of the orifice 77 forming a valve seat.

D'autre part, la cuvette 76 a un diamètre extérieur légèrement plus petit que le diamètre intérieur du prolongement cylindrique 75 du piston 74 de façon à ménager un espace annulaire 82 mettant en communication la chambre supérieure 78 avec la chambre 72.On the other hand, the bowl 76 has an outside diameter slightly smaller than the diameter inside of the cylindrical extension 75 of the piston 74 so as to provide an annular space 82 bringing the upper chamber 78 into communication with the chamber 72.

Le petit piston 80 est rappelé vers le haut par des ressorts 83 prenant appui sur la semelle 13 et sa course vers le bas est limitée par une butée 84.The small piston 80 is returned upwards by springs 83 bearing on the sole 13 and its downward travel is limited by a stop 84.

La jupe 76a de la cuvette 76 et la plaque d'appui 73 sont percées de petits canaux respectivement 85 et 86 mettant en communication la chambre supérieure 78 avec la cavité 70. De plus, la plaque d'appui 73 est percée de petits orifices 87 munis de clapets anti-retour qui mettent en communication la chambre 72 avec les petits canaux 86.The skirt 76a of the bowl 76 and the support plate 73 are pierced with small channels 85 and 86 respectively putting the upper chamber 78 into communication with the cavity 70. In addition, the support plate 73 is pierced with small orifices 87 fitted with non-return valves which put the chamber 72 in communication with the small channels 86.

Enfin, une conduite 89 munie d'une vanne 90 débouche entre le petit piston 80 et la semelle 13.Finally, a pipe 89 fitted with a valve 90 opens out between the small piston 80 and the sole 13.

La cavité 70 forme un réservoir de fluide qui remplit les chambres 72, 78 et 79 ainsi que les petits canaux 85 et 86.The cavity 70 forms a fluid reservoir which fills the chambers 72, 78 and 79 as well as the small channels 85 and 86.

Lors de la descente du serre-flan supérieur pour le préformage de la pièce, la vanne 90 est ouverte et l'air comprimé agit sur le petit piston 80 de façon à appliquer le clapet 81 sur son siège. L'orifice 77 est fermé, ce qui empêche le fluide de s'écouler de la chambre 78 vers la chambre 79 et par conséquent au coussin élastique 6 de fluer vers le bas.When lowering the upper blank holder for preforming the part, the valve 90 is open and the compressed air acts on the small piston 80 so as to apply the valve 81 to its seat. The orifice 77 is closed, which prevents the fluid from flowing from the chamber 78 towards the chamber 79 and consequently the elastic cushion 6 from flowing downwards.

Pendant l'opération de conformation finale par le poinçon (Fig. 10), l'alimentation en air comprimé est arrêtée. Sous l'effet de la pression exercée sur le coussin élastique 6 par le poinçon, le piston 74 descend, ce qui provoque par l'intermédiaire du fluide contenu dans la chambre 78 l'ouverture du clapet 81. Le fluide s'écoule de la chambre 78 vers la chambre 79, puis vers la cavité 70 par les petits canaux 85 et 86. Cette disposition permet de réguler le déplacement du piston 74 et d'absorber le volume excédentaire du coussin élastique 6 par rapport à celui déterminé par la surface de la pièce finie à obtenir.During the final shaping operation with the punch (Fig. 10), the supply of compressed air is stopped. Under the effect of the pressure exerted on the elastic cushion 6 by the punch, the piston 74 descends, which causes, via the fluid contained in the chamber 78, the opening of the valve 81. The fluid flows from the room 78 towards the chamber 79, then towards the cavity 70 by the small channels 85 and 86. This arrangement makes it possible to regulate the movement of the piston 74 and to absorb the excess volume of the elastic cushion 6 relative to that determined by the surface of the finished part at get.

En fin de cycle (Fig. 11), après la remontée du poinçon et du serre-flan supérieur, les ressorts de rappel 92 provoquent la remontée du piston 74 et des ressorts 83, la remontée du piston 80 obturant ainsi l'orifice 77 par le clapet 81.At the end of the cycle (Fig. 11), after raising the punch and the upper blank holder, the return springs 92 cause the piston 74 and the springs 83 to rise, the piston 80 rising thus closing the orifice 77 by the valve 81.

Sous l'effet de l'aspiration créée dans la chambre 70 par la remontée du piston 74, les petits clapets disposés dans les orifices 87 s'ouvrent et le fluide s'écoule de la cavité 70 vers la chambre 72 en passant par les canaux 86 et les orifices 87, puis de la chambre 72 vers la chambre 78 en passant par l'espace annulaire 82.Under the effect of the suction created in the chamber 70 by the ascent of the piston 74, the small valves arranged in the orifices 87 open and the fluid flows from the cavity 70 towards the chamber 72 via the channels 86 and the orifices 87, then from the chamber 72 to the chamber 78 passing through the annular space 82.

Selon encore une autre variante illustrée à la figure 12, le corps 1 est constitué d'une partie supérieure 100a solidaire du coulisseau extérieur, non représenté, de la presse, et d'une partie inférieure 100b distincte dont la face inférieure constitue le serre-flan périphérique supérieur.According to yet another variant illustrated in FIG. 12, the body 1 consists of an upper part 100a secured to the external slide, not shown, of the press, and of a separate lower part 100b, the lower face of which constitutes the clamp. upper peripheral blank.

Entre les deux parties 100a-100b du corps 1 est intercalé au moins un organe 101 modifiant la pénétration du serre-flan supérieur dans le coussin élastique 6. Cet organe 101 peut être constitué par exemple par un ressort ou par un vérin ou encore par tout autre système approprié limitant la hauteur de pénétration du serre-flan supérieur dans le coussin lorsque la pression dans ledit coussin devient supérieure à une valeur déterminée.Between the two parts 100a-100b of the body 1 is interposed at least one member 101 modifying the penetration of the upper blank holder in the elastic cushion 6. This member 101 can be constituted for example by a spring or by a jack or by any other another suitable system limiting the penetration height of the upper blank holder in the cushion when the pressure in said cushion becomes greater than a determined value.

Les moyens d'absorption du volume excédentaire du coussin élastique 6 peuvent être également formés par au moins une paroi latérale du bac 2 coopérant avec un organe constitué, par exemple par au moins un ressort ou un vérin, permettant de réguler le déplacement de ladite paroi latérale en fonction de la pression exercée dans le coussin élastique.The means for absorbing the excess volume of the elastic cushion 6 can also be formed by at least one side wall of the tank 2 cooperating with a member constituted, for example by at least one spring or a jack, making it possible to regulate the movement of said wall lateral as a function of the pressure exerted in the elastic cushion.

Le dispositif, selon la présente invention, s'applique non seulement dans le cas où le flan de tôle repose sur un serre-flan inférieur constitué par un cadre, mais également dans le cas, où le flan de tôle repose directement sur le coussin élastique, selon le FR-A-2.564.339, et dans le cas, où le flan de tôle est en appui sur la partie supérieure du bac de rétention du coussin élastique, selon le FR-A-2.590.814.The device according to the present invention is applicable not only in the case where the sheet metal blank rests on a lower blank holder formed by a frame, but also in the case where the sheet blank rests directly on the elastic cushion , according to FR-A-2,564,339, and in the case where the sheet blank is in abutment on the upper part of the retention tank of the elastic cushion, according to FR-A-2,590,814.

Claims (16)

  1. Method for pressing sheet materials formed by a sheet blank (4) placed on a support forming a bottom blank holder (2a), the said device comprising a cushion (6) made from elastic material housed in a retaining box (2), means for preforming the sheet metal blank consisting of an outer slide bearing a top blank holder (1a) and means for effecting the final forming of the said sheet blank consisting of a central slide acting on a punch (4), and means (10) for absorbing the excess volume of the elastic cushion (6), characterised in that the absorption means (10) can be moved during the final forming of the piece, the said movement being regulated by a device (11-31-54-74) for regulating as a function firstly of the pressure applied by the cushion (6) made from an elastic material during the said stage and secondly of the volume determined by the surface area of the finished piece to be obtained.
  2. Pressing device according to Claim 1, characterised in that the means (10) for absorbing the excess volume of the elastic cushion (6) are formed by the bottom (5) of the cushion retaining box (2).
  3. Pressing device according to Claim 1, characterised in that the means (10) for absorbing the excess volume of the elastic cushion (6) are formed by at least one side wall of the cushion retaining box.
  4. Pressing device according to Claim 1, characterised in that the means (10) for absorbing the excess volume of the elastic cushion (6) consist of the top blank holder (1a).
  5. Pressing device according to Claim 1, characterised in that the regulating device consists of a movable piston (11) interacting with a multi-plate brake (12) comprising upper friction plates (12a) secured to the piston (11) and lower friction plates (12b) secured to a fixed sole plate (13) and interposed between the said upper friction plates, and with a return device (14).
  6. Pressing device according to Claim 5, characterised in that the multi-plate brake (12) is actuated by at least one control jack (16) acting on a rod articulated on two levers (19, 20) forming a toggle for clamping the friction plates (12a, 12b).
  7. Pressing device according to Claim 1, characterised in that the regulating device consists of a movable piston (31) interacting with a reversible screw (30) connected so as to rotate with the said piston and provided with a belt brake (33, 36, 39), and with a return device (35).
  8. Pressing device according to Claim 7, characterised in that the belt brake comprises a rotatable nut (33) provided on its periphery with a groove (33b) for guiding a belt (36), the tension of which is controlled by a jack (39).
  9. Pressing device according to Claim 1, characterised in that the regulating device consists of a movable piston (31) interacting with a reversible screw (30) connected so as to rotate with the said piston and actuated by a step-by-step control mechanism (33, 40).
  10. Pressing device according to Claim 9, characterised in that the step-by-step control mechanism is formed by a rotatable nut (30) provided on its periphery with meshing means consisting of a toothed groove (33c) interacting with a worm (40).
  11. Pressing device according to Claim 1, characterised in that the regulating device consists of a movable piston (54) interacting with a hydraulic jack (50).
  12. Pressing device according to Claim 11, characterised in that the hydraulic jack (50) is controlled by a hydraulic circuit comprising notably a pressure reducer (58) with programmed proportioning control.
  13. Pressing device according to Claim 1, characterised in that the regulating device consists of a movable piston (74) interacting with a hydraulic valve (81) controlled by a pneumatic valve (89, 90).
  14. Pressing device according to Claim 13, characterised in that the hydraulic valve (81) is carried by a piston (80) subjected to the pressure of compressed air distributed through the pneumatic valve (89, 90) and sliding in a cup (76), the top wall of which has a central orifice (77) forming a valve seat.
  15. Pressing device according to Claim 14, characterised in that the cup (76) defines with the piston (74) an upper chamber (78) and with the small piston (80) an inner chamber (79), the said chambers (78, 79) being filled with a fluid and communicating with each other through the central orifice (77).
  16. Pressing device according to one of Claims 13 to 15, characterised in that it includes a cylindrical cavity (70) constituting a fluid reservoir communicating on the one hand with the upper chamber (78) and on the other hand with the inner chamber (79).
EP89403590A 1988-12-30 1989-12-20 Method and device for deep-drawing sheet materials on an elsatic formation lower die Expired - Lifetime EP0376809B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT89403590T ATE88383T1 (en) 1988-12-30 1989-12-20 METHOD AND DEVICE FOR PRESSING SHEET MATERIALS ON A DIE OF ELASTIC FORM.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8817526 1988-12-30
FR8817526A FR2641217B1 (en) 1988-12-30 1988-12-30 METHOD AND DEVICE FOR SCRAPPING SHEET MATERIALS ON AN ELASTIC FORMING MATRIX

Publications (2)

Publication Number Publication Date
EP0376809A1 EP0376809A1 (en) 1990-07-04
EP0376809B1 true EP0376809B1 (en) 1993-04-21

Family

ID=9373660

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89403590A Expired - Lifetime EP0376809B1 (en) 1988-12-30 1989-12-20 Method and device for deep-drawing sheet materials on an elsatic formation lower die

Country Status (17)

Country Link
US (1) US5081859A (en)
EP (1) EP0376809B1 (en)
JP (1) JPH02290628A (en)
KR (1) KR900009259A (en)
CN (1) CN1025296C (en)
AT (1) ATE88383T1 (en)
AU (1) AU624459B2 (en)
BR (1) BR8906861A (en)
CA (1) CA2006772A1 (en)
CZ (1) CZ283163B6 (en)
DD (1) DD294438A5 (en)
DE (1) DE68906141T2 (en)
FR (1) FR2641217B1 (en)
HU (1) HU204000B (en)
RO (1) RO107565B1 (en)
RU (1) RU2018385C1 (en)
ZA (1) ZA899723B (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2641217B1 (en) * 1988-12-30 1994-04-01 Isoform METHOD AND DEVICE FOR SCRAPPING SHEET MATERIALS ON AN ELASTIC FORMING MATRIX
FR2668982B1 (en) * 1990-11-13 1995-07-21 Ascometal Sa METHOD AND DEVICE FOR MANUFACTURING A SOUNDPROOF WHEEL, PARTICULARLY FOR RAIL VEHICLE AND WHEEL OBTAINED BY THIS PROCESS.
FR2670408A1 (en) * 1990-12-18 1992-06-19 Isoform DEVICE FOR STITCHING SHEET MATERIALS, ESPECIALLY FLANGES OF SHEET.
FR2683168B1 (en) * 1991-11-04 1994-03-04 Isoform DEVICE FOR STAMPING SHEET MATERIALS, PARTICULARLY SHEET SHEET.
FR2691653B1 (en) * 1992-05-27 1994-08-26 Isoform Device for stamping sheet materials on a forming matrix of elastic material.
FR2715335B1 (en) * 1994-01-21 1996-04-05 Lorraine Laminage Device for stamping a sheet blank.
US6029486A (en) * 1998-04-23 2000-02-29 Amada Metrecs Company, Limited Forming method, forming tools and elastic punch
US7910039B2 (en) * 2008-03-10 2011-03-22 Jamin Micarelli Rapid cycling press for forming a composite article
JP2011073057A (en) * 2009-09-02 2011-04-14 Enami Seiki:Kk Press machining device and shaft portion restriction device
US10525519B2 (en) 2009-10-21 2020-01-07 Stolle Machinery Company, Llc Container, and selectively formed cup, tooling and associated method for providing same
US8556618B2 (en) * 2011-04-07 2013-10-15 Spirit Aerosystems, Inc. Method and bladder apparatus for forming composite parts
KR101197089B1 (en) 2011-04-19 2012-11-07 한국과학기술원 The forging device of asymmetry axial product
JP5611257B2 (en) * 2012-03-13 2014-10-22 パナソニック株式会社 Metal laminate film molding method and molding apparatus therefor
RU2576970C1 (en) * 2014-07-21 2016-03-10 Федеральное государственное бюджетное образовательное учреждение высшего образования "Тульский государственный университет" (ТулГУ) Production of deep-profile corrugated membrane
EP3523065A4 (en) * 2016-10-06 2020-06-17 Stolle Machinery Company, LLC Container, and selectively formed cup, tooling and associated method for providing same
US10773291B2 (en) 2017-05-24 2020-09-15 Polyurethane Products Universal radius forming system
CN107199448A (en) * 2017-06-13 2017-09-26 新乡市振英机械设备有限公司 A kind of press-loading device of spin vibration sieve dust cover
CN115007729A (en) * 2022-06-22 2022-09-06 四川航天长征装备制造有限公司 Elastic cushion for forming rubber bag
CN117019989B (en) * 2023-10-08 2023-12-15 江苏迅隆电源有限公司 Aluminum alloy casting stamping equipment with alternating stress mode

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2719500A (en) * 1950-07-28 1955-10-04 Northrop Aircraft Inc Flange forming press
US2783728A (en) * 1951-09-12 1957-03-05 Lake Erie Engineering Corp Apparatus for pressing sheet metal shapes
US3262294A (en) * 1963-08-16 1966-07-26 Cincinnati Milling Machine Co Hydraulic forming press
US3552165A (en) * 1968-05-22 1971-01-05 John H Taylor Domestic-pan-forming device
SU615998A1 (en) * 1976-02-04 1978-07-25 Предприятие П/Я А-1139 All-purpose die set with elastic female die
SU799869A1 (en) * 1978-02-03 1981-01-30 Предприятие П/Я В-8772 Combination die for blanking profile, drawing and rim bending
JPS60133933A (en) * 1983-12-21 1985-07-17 Honda Motor Co Ltd Press forming method
JPS60221134A (en) * 1984-04-16 1985-11-05 Aida Eng Ltd Press die
FR2564339B1 (en) * 1984-05-17 1987-12-24 Usinor METHOD AND DEVICE FOR STAMPING SHEETS.
FR2590814B1 (en) * 1985-12-04 1988-02-26 Usinor METHOD AND DEVICE FOR SCRAPPING LOW ELONGATION SHEETS
FR2615421B1 (en) * 1987-05-22 1989-08-18 Isoform PROCESS FOR CUTTING THIN SHEETS, ESPECIALLY SHEET AND ELASTOMERIC MATERIAL FOR USE IN THIS PROCESS
JPH07115093B2 (en) * 1987-10-23 1995-12-13 廣 三浦 Resin mold for sheet metal press and manufacturing method thereof
FR2641217B1 (en) * 1988-12-30 1994-04-01 Isoform METHOD AND DEVICE FOR SCRAPPING SHEET MATERIALS ON AN ELASTIC FORMING MATRIX

Also Published As

Publication number Publication date
CS8907513A2 (en) 1991-12-17
US5081859A (en) 1992-01-21
DE68906141D1 (en) 1993-05-27
ZA899723B (en) 1991-08-28
HU204000B (en) 1991-11-28
HUT53562A (en) 1990-11-28
HU896791D0 (en) 1990-03-28
KR900009259A (en) 1990-07-04
ATE88383T1 (en) 1993-05-15
AU4700689A (en) 1990-07-05
DD294438A5 (en) 1991-10-02
RU2018385C1 (en) 1994-08-30
BR8906861A (en) 1990-09-25
CN1025296C (en) 1994-07-06
JPH02290628A (en) 1990-11-30
DE68906141T2 (en) 1993-12-02
FR2641217B1 (en) 1994-04-01
CN1043645A (en) 1990-07-11
AU624459B2 (en) 1992-06-11
EP0376809A1 (en) 1990-07-04
FR2641217A1 (en) 1990-07-06
CA2006772A1 (en) 1990-06-30
CZ283163B6 (en) 1998-01-14
RO107565B1 (en) 1993-12-30

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